1. Field of the Invention
The present invention generally relates to networking and more specifically to an multi-rate interface between a MAC layer and a PHY layer.
2. Background Art
In computer network systems there is typically a natural division between chips handling the physical layer, which is responsible for transmitting data on the network, and the system chips, which perform logical operations with data transmitted on the network. Each port in an Ethernet device is typically composed of a system chip, which includes a media access controller (MAC) layer or “MAC” and a physical (PHY) layer or “PHY”. Most multi-port Ethernet devices integrate one or more MACs into one system chip (MAC chip) as well as one or more PHYs into another chip (PHY chip). An interface is required on each chip to transfer signals between the MACs and the PHYs.
IEEE standard 802.3 standards define protocols for interfaces between a MAC layer and a PHY for specific known data rate on a backplane link. However, if the data rate on a backplane link to a PHY is variable then there is lack of an interface that can support the variable data rate. Methods and systems are needed to overcome the above deficiencies.